Optical device for wavelength locking

Abstract

An optical device comprising a 1×2 optical coupler on a planar substrate and a waveguide on the planar substrate, the waveguide having a first arm and a second arm coupled to the 1×2 optical coupler. The device also comprises an optical resonator on the planar substrate, wherein the optical resonator is optically coupled to the first arm and the optical resonator is substantially athermalized.

What is claimed is: 
     
       1. An optical device, comprising:
 a 1×2 optical coupler on a planar substrate; 
 a waveguide structure on said planar substrate, said waveguide structure having a first waveguide arm and a second waveguide arm coupled to said 1×2 optical coupler; and 
 an optical resonator on said planar substrate, wherein said optical resonator is optically coupled to said first waveguide arm and said optical resonator is substantially athermalized 
 wherein 
 said substantially athermalized optical resonator includes:
 a sequence of end-coupled and spaced-apart segments of a light-guiding core having a thermo-optic coefficient, and, 
 optical material between adjacent ones of said segments, said optical material having thermo-optic coefficient of opposite sign than a sign of said thermo-optic coefficient of said spaced-apart segments. 
 
 
     
     
       2. The optical device of  claim 1 , further including:
 first and second photo-detectors located on said planar substrate and optically coupled to output ends of said first waveguide arm and said second waveguide arm, respectively; and 
 a control module located on said planar substrate, wherein said control module is electrically coupled to said first and second photo-detectors and is configured to control an output wavelength of a light-source optically coupled to said 1×2 optical coupler. 
 
     
     
       3. The optical device of  claim 2 , further including a laser light-source optically coupled to said 1×2 optical coupler and wherein said control module is configured to control light output from said light-source. 
     
     
       4. The optical device of  claim 1 , wherein said optical resonator further includes an adjustable optical coupler optically coupled to said first waveguide arm and to a light-guiding portion of said resonator. 
     
     
       5. The optical device of  claim 1 , wherein said optical resonator further includes a phase shifter optically coupled to a light-guiding core of said resonator. 
     
     
       6. The optical device of  claim 1 , wherein said optical resonator further includes a phase shifter optically coupled to portions of said light-guiding core which do not include said second core. 
     
     
       7. The optical device of  claim 1 , further including a second optical resonator on said planar substrate, wherein said second optical resonator is optically coupled to said second waveguide arm and said second optical resonator is substantially athermalized. 
     
     
       8. The optical device of  claim 1 , further including:
 an input waveguide on said planar substrate, one end of said input waveguide optically coupled to a light-source and another end of said input waveguide optically coupled to said 1×2 optical coupler; and 
 a tap port optically coupled to said input waveguide, said tap port configured route a portion of a light from said light-source to a control module, said control module configured to adjust light-transmission intensity from said light-source. 
 
     
     
       9. The optical device of  claim 1 , wherein the waveguide structure is a distinct structure from the optical resonator. 
     
     
       10. The optical device of  claim 1 , wherein the 1×2 optical coupler is a directional coupler. 
     
     
       11. The optical device of  claim 1 , wherein the 1×2 optical coupler is a 50/50 Y-splitter. 
     
     
       12. An optical device, comprising:
 a 1×2 optical coupler on a planar substrate; 
 a waveguide structure on said planar substrate, said waveguide structure having a first waveguide arm and a second waveguide arm coupled to said 1×2 optical coupler; and 
 an optical resonator on said planar substrate, wherein said optical resonator is optically coupled to said first waveguide arm and said optical resonator is substantially athermalized, wherein said substantially athermalized optical resonator includes:
 a sequence of spaced-apart and end-coupled segments of a light-guiding core, each segment having a thermo-optic coefficient of a first sign and, 
 optical material between the segments, the material having a thermo-optic coefficient of an opposite second sign, and 
 
 wherein said first core portions progressively decreases in width in directions distal to interfaces between said light-guiding core and the optical material between the segments. 
 
     
     
       13. An optical device, comprising:
 a 1×2 optical coupler on a planar substrate; 
 a waveguide structure on said planar substrate, said waveguide structure having a first waveguide arm and a second waveguide arm coupled to said 1×2 optical coupler; and 
 an optical resonator on said planar substrate, wherein said optical resonator is optically coupled to said first waveguide arm and said optical resonator is substantially athermalized, wherein said substantially athermalized optical resonator includes:
 a sequence of spaced-apart and end-coupled segments of a light-guiding core, each segment having a thermo-optic coefficient of a first sign, and, 
 optical material between the segments, the material having a thermo-optic coefficient of an opposite second sign. 
 
 
     
     
       14. An optical device, comprising:
 a 1×2 optical coupler on a planar substrate; 
 a waveguide structure on said planar substrate, said waveguide structure having a first waveguide arm and a second waveguide arm coupled to said 1×2 optical coupler; 
 an optical resonator on said planar substrate, wherein said optical resonator is optically coupled to said first waveguide arm and said optical resonator is substantially athermalized; and 
 a second optical resonator on said planar substrate, wherein said second optical resonator is optically coupled to said second waveguide arm and said second optical resonator is substantially athermalized, wherein combined transmittance curves from said optical resonator and said second optical resonator includes a v-shaped notch centered in a C or L optical communication band. 
 
     
     
       15. An optical device, comprising:
 a 1×2 optical coupler on a planar substrate; 
 a waveguide structure on said planar substrate, said waveguide structure having a first waveguide arm and a second waveguide arm coupled to said 1×2 optical coupler; 
 first and second optical resonators on said planar substrate, wherein said first optical resonator is optically coupled to said first waveguide arm and said second optical resonator is optically coupled to said second waveguide arm; 
 first and second photo-detectors located on said planar substrate and optically coupled to output ends of said first waveguide arm and said second waveguide arm, respectively; and 
 a control module located on said planar substrate, wherein said control module is electrically coupled to said first and second photo-detectors and is configured to control an output wavelength of a light-source optically coupled to said 1×2 optical coupler, wherein 
 combined transmittance curves from said first optical resonator and said second optical resonator includes a v-shaped notch centered in a C or L optical communication band. 
 
     
     
       16. The optical device of  claim 15 , wherein said first optical resonator and said second optical resonator are both substantially athermalized. 
     
     
       17. The optical device of  claim 15 , wherein the waveguide structure is a distinct structure from the optical resonator. 
     
     
       18. The optical device of  claim 15 , wherein the 1×2 optical coupler is a directional coupler. 
     
     
       19. The optical device of  claim 15 , wherein the 1×2 optical coupler is a 50/50 Y-splitter.